how do you differenciate ideal and real gases

Technically, there are no ideal gases but several approach being ideal gases. One tells by experiment. If they obey the ideal gas laws they are ideal; if not, they are not ideal gases.

I think I used the wrong word in my response. I should not have said technically, there..... A better word would be practically (in practice) there are no ideal......

To differentiate between ideal and real gases, you can consider the following factors:

1. Assumptions: Ideal gases follow certain assumptions, while real gases do not. The ideal gas law assumes that gas particles have no volume and do not interact with each other. In contrast, real gases have volume and experience intermolecular forces.

2. Behavior at low pressures: Ideal gases closely follow the ideal gas law, which states that PV = nRT (where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature in Kelvin). Real gases tend to deviate from this behavior at high pressures and low temperatures.

3. Intermolecular forces: Real gases experience intermolecular forces, such as London dispersion forces, dipole-dipole interactions, or hydrogen bonding. These forces affect the behavior of the gas, causing deviations from ideal gas behavior. Ideal gases assume negligible or no intermolecular forces.

4. Compressibility: Real gases are compressible, meaning their volume can be reduced under high pressure. In contrast, ideal gases are considered perfectly compressible, where volume can be reduced without limit. However, in reality, this is not possible as gases have volume and intermolecular forces.

It's important to note that no gas is truly ideal or real. Rather, these terms are used as simplified models to explain the behavior of gases under different conditions.